New to MS Project and MS Project 2016 PRO. I’m 80% done creating my first project and really struggling with resources / task duration. For example, I have 4 sub-tasks assigned to a single resource that in reality take 2 hours per task (8-hours total). However, the single resource has 2 full days to complete the 4 tasks (16-hours). Any 1 of the 4 tasks can begin day 1 or day 2…important that all 4 tasks completed by end of day 2. Should I use fixed duration, fixed units or fixed work? Can I do this is Auto Scheduled mode? Or must it be manual? Any help is much appreciated. Thanks.

K –
There’s several different ways this could be answered depending on other factors. But to provide a simple answer, my personal opinion is that 2 hour tasks are too small. I’d recommend combining them into one task of 8 hours. If you need the task to show a two day duration, I’d suggest Fixed Units and the assigned resource having an assignment units of 50%. If there’s no reason the task MUST take 2 days, then also use Fixed Units, assign the resource at full allocation, and let the scheduling tool reflect that it will take less than 2 days to complete. (If you force a duration, you’re manually constraining the duration and preventing the scheduling engine from doing what its designed to do)

Overall, I’d recommend keeping the schedule as simple as possible. Understand what you need to track and set up the schedule accordingly. Meaning, is there a real reason each 2 hour effort must be an independent task? Are they each creating specific key deliverables that must be tracked independently? Does each need different assigned resources? Or does each have different dependency relationships? So there could be valid reasons, but in this case, it’s the same resource assigned and it sounds like you just need to make sure that set of work items is completed. So do it as simply as possible in the schedule.

Both Fixed Duration and Fixed Units will work, the question is what do want MS Project to NOT change if you adjust the task. If it is more critical that the assignment units value doesn’t change, then use Fixed Units. If the Duration is more critical and that must not change, use Fixed Duration. Generally speaking, here’s how I use them.
Fixed Units applies more to project resources. For example, Bob is on the project at 50% and we don’t want project to dynamically change that value to something else.
Fixed Duration applies more towards external events where work isn’t being tracked at the resource level. For example, the phone company needs 2 days to install the equipment after it arrives.

Here’s where the complexity comes into the equation and where I’m having problems. There are 16 tasks that must be completed over the span of 5 days. Two resources handle the work load, each working 100% of their time with some tasks utilizing a single resource, and others where both resources are working on a task (one resource handles a higher percentage of the task). For example, a task is 20 hours with resource #1 responsible for for 6 hours and resource #2 responsible for the remaining 14 hours. Also, some tasks are just a few hours while others more. The tasks don’t have to be done in order, they just have to be done within the span of 5 days. I’d like to work using Fixed Units which seems to make sense. Here are some further examples of what I’m working with:
Task #1. 2 hours – Resource #1
Task #2. 14 hours – Resource #1 responsible for 2 hours and resource #2 for 12 hours
Task #3. 6 hours – Resource #2
Task #4 thru #16. All similar to above

K
To reiterate, you’ve got 16 items that need to be done over the course of a week and you’ll be assigning 2 people to do these items at 100%. There also doesn’t appear to be a specific sequence for the items and the primary work volume on these 16 items can alternate.

Generally speaking, project management guidelines talk about keeping tasks within an “80 hour” rule. Stated another way, we want deliverables on at most, a 2 week cycle. There is however the other side of the equation which says don’t make the tasks so small that your schedule ends up with hundreds/thousands of tasks that are less than a day in duration. You’ll end up with a scheduling nightmare. So there’s a balance that you need to find. Is it worth spending a 3 days or a week trying to figure out how to set up your 16 items as 16 tasks, or is it easier to simply note that 40 hours is required for a block of 16 items which can be managed from a to-do list attached to the task?

As I’m sure you’re finding out, there’s a lot of complexity in setting up those 16 tasks, especially when the two assigned resources have vastly different work assignments on each. Without the right leveling options your schedule will most likely contain lots of non-working gaps. With the right leveling options, the gaps can be removed, but the result may be resource #1 working on items 1-3 while resource #2 is working on the only the first item.

So, based on what your describing, my recommendation is to keep it simple. On a piece of paper, a spreadsheet, whatever, map out the 16 items to be completed along with the work for each resource. Sum up the total resource estimates. Make allocation adjustments if needed. Meaning if resource #1 is allocated 68 hours of work to be completed in 5 days, that means that about 28 hours of that work should probably be shifted to resource #2. Basically, try to get the balance as close to 40 hours for each resource as possible. If both resources are somewhat balanced and both are well over 40 hours, then you have an expected duration problem. Assuming they are both 40 hours or less, add the task to the schedule with the refined allocations. Add a note to the tasks summarizing the 16 items this covers and the individual estimates to the schedule task.
Bottom line, ask yourself this. What is the driving reason that means I need to create these 16 work items as individual tasks? If there isn’t one, simplify.

Here is a link to a leveling article I wrote. https://www.mpug.com/articles/resource-leveling-resolution-options/
Look specifically at the section on “Leveling can adjust individual assignments on a task”. It provides examples of how MS Project can shift start dates of assigned resources or require that both are available before a task can be started.